Tube connector

ABSTRACT

A barbed insert is fitted into the terminal end of a plastic tube. The tube and attached insert are then positioned through a hole in a plate. The insert is chamfered at one end to engage a counterbore opening in the plate and hold the plastic tube and attached insert in a fixed position in the plate.

United States Patent Inventor Karl A. Brandenberg Hayward, Calif.794,334

Jan. 27, 1969 Mar. 30, I971 The Aro Corporation Bryan, Ohio Appl. No.Filed Patented Assignee TUBE CONNECTOR 3 Claims, 3 Drawing Figs.

U.S.Cl 285/213, 285/242 lnt.Cl Fl6l4l/00 Field of Search 285/2 I 3,

[56] References Cited UNITED STATES PATENTS 2,092,358 9/1937Robertson..... 285/213 3,336,055 8/1967 Poll et al 285/158X FOREIGNPATENTS 569,632 11/1957 Italy 285/242 626,546 l0/l96l Italy 285/242Primary Examiner-Dave W. Arola Attorney-Molinare, Allegetti, Newitt &Witcoff ABSTRACT: A barbed insert is fitted into the terminal end of aplastic tube. The tube and attached insert are then positioned through ahole in a plate. The insert is chamfered at one end to engage acounterbore opening in the plate and hold the plastic tube and attachedinsert in a fixed position in the plate.

PATENTEuuARaomn 3572772 Fla] I luvau'roa Kan. A. Banuosuum TUBECONNECTOR BACKGROUND OF THE INVENTION This invention relates to anassembly for connecting plastic tubes of the type used for pneumaticcircuits to a plate.

With the development of pneumatic control systems, for example, forindustrial machine applications, pneumatic card and tape readers havebeen developed. Such devices require a relatively high number ofpneumatic output and input eonduits often confined in a small space.

Thus, one of the problems encountered when designing a reader head, forexample, concerns the physical positioning and maintaining in positionof the many pneumatic input tubes to the head. Known methods forretaining tubes by providing sleeves for fixing the tubes to the headprove to be too cumbersome and not compact enough to allow simple designand inexpensive construction.

The following characteristics are desired for a tube connector assemblythat will be practical for such applications:

I. The distance between tubes must be minimized;

2. The tubes must be retained tightly so that they will not disconnectdue to pressure or pulling;

3. The tubes must be sealed at both high (up to 150 p.s.i.g.)

and low pressures; and

4. Finally, the separate tubes must be easily installed and likewiseeasily removable and replaceable.

SUMMARY OF THE INVENTION In a principal aspect the present invention ofa tube connector assembly for connecting a plastic tube to a platecomprises an insert having a barb thereon positioned in the end'of thetube. The tube is then fitted through an opening in the plate. Theinsert in cooperation with the plate includes means which prevent theinsert and attached tube from being pulled through the plate.

It is thus an object of the present invention to provide an improvedtube connector assembly.

It is a further object of the present invention to provide a tubeconnector assembly which pennits positioning the tubes very closetogether.

Still another object of the present invention is to provide a tubeconnector assembly which maintains a connection between the tube andplate over a wide range of pressures so that the tubes cannot bedisconnected due to pressure or' pulling easily be installed andremoved.

One further object of the present invention is to provide a tubeconnector assembly constructed so that tubes may easily be installed andremoved.

One further object of the present invention is to provide an inexpensiveand relatively simple tube connector assembly.

These and other objects, advantages and features of the invention willbeset forth in greater detail in the description which follows.

BRIEF DESCRIPTIONOF THE DRAWINGS In the detailed-description whichfollows reference will be made to the drawings comprised of thefollowing FIGS.:

FIG. 1 is a cross-sectional view of a first embodiment of the improvedtube connector assembly of the invention;

FIG. 2 is a cross-sectional view of a second preferred embodiment of theinvention; and

FIG. 3 is an exploded perspective view of the assembly shown in FIG. I.

DESCRIPTION OF THE PREFERRED EMBODIMENTS an opening I2 in a body 14. Thebody 14 may be a reader head, for example.

The tube connector assembly includes a hollow insert I6 and a plate 18.The insert 16 and plate 18 are constructed to cooperate not only witheach other, but also with the tube It) so that the tube 10 and attachedinsert I6 may be easily positioned in a fixed, locked relationshipthrough the plate 18. 1 The insert 16 includes a central passage 17 withan axis 19 and also includes a tube-receiving end 20 adapted to fit intoa terminal end 22 of the tube I0. The tube-receiving end 20 includes acircumferential barb 24. The barb 24 is formed by the intersection of aradial surface 28 and an inclined or frustoconical surface 26. Thus, atthe receiving end 20 of the insert I6 the surface 26 has a diameter lessthan the inside diameter of the tube 10', whereas, at the opposite endof the surface 26, the diameter is greater than the inside diameter ofthe tube I0 but less than the outside diameter of the tube 10. Thislatter described surface 26 diameter is approximately equal to thediameter of a surface of revolution halfway through the wall thicknessof the tube I0.

The frustoconical surface 26 intersects the radial surface 28 to formthe grasping portion of the barb 24. The radial surface 28 terminates atan outside cylindrical surface 30 of the insert 16. The outside surface30 has a diameter substantially equal to the diameter of the inside ofthe tube I0. The opposite end 31 of the insert 16 is provided with aflange 32 defined by a second radial surface or neck surface 34 and asecond cylindrical or chamfered surface 36. The neck surface 34 isadapted to engage the end surface 35 of the tube I0 thereby limiting thetravel of the tube 10 inserted over the barb 24.

The second cylindrical surface 36 is chamfered or beveled outwardly fromthe intersection of the neck surface 34 and the surface 36. The line ofintersection of the neck surface 34 and the surface 36 is substantiallycoincident with the outside cylindrical surface of the tube 10. Thesurface 36 fortns an angle of about l0" with the outside cylindricalsurface 30 of insert 16.

The plate 18 includes a cylindrical passage 38 having a diametersubstantially equal to the outside diameter of the tube I0. Plate 18also includes a counterbore passage 40 defined at one end of thecylindrical passage 38. The counterbore passage 40 is adapted to engagethe chamfercd surface 36 of the insert 16 thereby holding the insert 16in a substantially fixed position in the plate I8 when the insert I6 isdirected or pulled to the left. The insert 16 and attached tube 10 maybe removed from the plate 18 by displacing the insert 16 and tube It) tothe right as shown in FIG. I.

To assemble the configuration reference is made especially to FIG. 3.There the plastic tube 10 has been inserted through the plate 118. Thebarbed insert 16 is then inserted into the plastic tube 10 so that theterminal end 22 of the tube It) engages the radial neck surface 34. Thetube It) and attached insert are pulled up through the plate 18. Whenbeing pulled through the plate 18, the barb 24 of the insert 16 deformsthe plastic tube slightly and wedges the tube I0 in position within theplate 18. The tube 10 is defonned because the insert I6 is made of amaterial, preferrably metal, which is relatively harder than thematerial from which the tube I0, generally plastic or rubber, is formed.The chamfered surface 36 engages the counterbore passage 40 to preventthe tube 10 and insert 16 from being pulled through the plate 18.

In practice, the plate 18 is provided with a plurality of tubes 10attached in the manner just described. The plate I8 and attached tubesare then positioned, for example, against a body 14 as shown in FIGS. Iand 3 with an intervening gasket 42 to provide a seal. The plate 18 isthus fastened to the body I4 through the gasket 42 thereby holding theassembly in a locked configuration. To remove or replace the tubes inthe assembly, the plate 18 is disconnected from the body It and theassembly process is reversed.

Referring now to FIG. 2 there is shown an alternative embodiment of theinvention. The embodiment shown in FIG. 2 is numbered in the same manneras the embodiment of FIGS. 1 and 3 except where differences occur. InFIG. 2 the construction of the insert I6 is varied by providing acylindricallyshaped flange 44. The flange 44 includes a nonehamferedcylindrical outer surface 46 which is concentric with the outsidesurface of the insert 16. The flange 44 mates with a correspondingcounterbore opening 48 provided in the plate 18. Thus, where theembodiment described in FIG. 1 had a surface chamfered at orthereabouts, the embodiment disclosed in FIG. 2 is provided with anonchamfered flange 44.

lelaim:

l. A tube connector assembly for grasping and connecting with theterminal end of a cylindrically-shaped plastic tube which, whenassembled, comprises in combination:

a cylindrically-shaped hollow insert inserted into the terminal end ofthe plastic tube, said insert being fabricated from a materialrelatively harder than said plastic tube, said insert having at leastone tube-receiving end, said tube-receiving end having an externaldiameter no greater than the inside diameter of said plastic tube whensaid assembly is in the unassembled condition, a barb defined on theoutside surface of said insert adjacent said tube-receiving end, saidbarb extending radially outward to define an external diameter on saidinsert greater than the inside diameter of said tube in the unassembledcondition, but less than the outside diameter of said tube in theunassembled condition, said barb deforming said tube upon insertiontherein, said insert also including flange means at the end of saidinsert opposite said tube-receiving end, at least a portion of saidflange means having a diameter greater than the outside diameter of saidtube in the unassembled conditions; and

a plate having an opening therethrough, said opening having a diametersubstantially equal to the outside diameter of said tube in theunassembled condition, said opening receiving said tube with said insertpositioned in the terminal end of said tube, said plate including meansfor cooperating with said insert flange means to prevent said insert andattached tube from passing completely through said opening therebyholding said tube and said insert in a fixed position in said plate.

2. The assembly of claim 1 wherein said flange means for holding saidinsert in position in said plate include a flange defined on said insertopposite said tube-receiving end, said flange also providing a stop forsaid tube fitted on said insert.

3. The assembly of claim I wherein said flange means comprises achamfered flange, said chamfered flange having a neck surface mated withthe terminal end surface of said tube, said flange flaring outwardlyfrom said neck surface, said plate including a counterbore adapted toreceive said chamfered flange,

1. A tube connector assembly for grasping and connecting with theterminal end of a cylindrically-shaped plastic tube which, whenassembled, comprises in combination: a cylindrically-shaped hollowinsert inserted into the terminal end of the plastic tube, said insertbeing fabricated from a material relatively harder than said plastictube, said insert having at least one tube-receiving end, saidtube-receiving end having an external diameter no greater than theinside diameter of said plastic tube when said assembly is in theunassembled condition, a barb defined on the outside surface of saidinsert adjacent said tube-receiving end, said barb extending radiallyoutward to define an external diameter on said insert greater than theinside diameter of said tube in the unassembled condition, but less thanthe outside diameter of said tube in the unassembled condition, saidbarb deforming said tube upon insertion therein, said insert alsoincluding flange means at the end of said insert opposite saidtube-receiving end, at least a portion of said flange means having adiameter greater than the outside diameter of said tube in theunassembled conditions; and a plate having an opening therethrough, saidopening having a diameter substantially equal to the outside diameter ofsaid tube in the unassembled condition, said opening receiving said tubewith said insert positioned in the terminal end of said tube, said plateincluding means for cooperating with said insert flange means to preventsaid insert and attached tube from passing completely through saidopening thereby holding said tube and said insert in a fixed position insaid plate.
 2. The assembly of claim 1 wherein said flange means forholding said insert in position in said plate include a flange definedon said insert opposite said tube-receiving end, said flange alsoproviding a stop for said tube fitted on said insert.
 3. The assembly ofclaim 1 wherein said flange means comprises a chamfered flange, saidchamfered flange having a neck surface mated with the terminal endsurface of said tube, said flange flaring outwardly from said necksurface, said plate including a counterbore adapted to receive saidchamfered flange.